Study Finds Suboptimal Use of Adjuvant Endocrine Therapy in Breast Cancer
In a retrospective cohort study reported in JAMA Oncology, Daly et al found that recommended use of adjuvant endocrine therapy for breast cancer improved in the United States between 2004 and 2013 but remains suboptimal.
The study included data on 981,729 women with stage I to III breast cancer from the National Cancer Database for January 2004 to December 2013. Women receiving all or part of their treatment at reporting institutions were included in the analysis.
Increasing Use
Patients had a mean age of 61 years; 818,435 had hormone receptor–positive disease and 163,294 had hormone receptor–negative disease. Among those with hormone receptor–positive cancer, receipt of adjuvant endocrine therapy increased from 69.8% in 2004 to 82.4% in 2013. Among those with hormone receptor–negative disease, receipt of adjuvant endocrine therapy decreased from 5.2% in 2004 to 3.4% in 2013. Adherence at the hospital level, defined as receipt of therapy by 80% or more of patients with hormone receptor–positive disease, increased from 40.2% to 69.2%.
Factors Associated With Use
Receipt of appropriate therapy varied significantly by age (adjusted odds ratio [OR] = 0.59 for patients aged ≥ 80 years vs 60–69 years), race (adjusted ORs = 0.87 and 0.88 for African American and Hispanic vs white patients), geographic location (adjusted ORs = 0.48, 0.55, and 0.52 for West South Central, Mountain, and Pacific vs New England census regions), and receptor status (adjusted ORs = 0.21 and 0.75 for estrogen receptor–negative/progesterone receptor–positive and estrogen receptor–positive/ progesterone receptor–negative vs estrogen receptor–positive/ progesterone receptor–positive disease).
Use of both surgery and radiotherapy had the most significant positive association with receipt of therapy: Compared with women receiving mastectomy and radiotherapy, adjusted odds ratios were 0.13 for lumpectomy/no radiotherapy, 0.36 for mastectomy/no radiotherapy, and 0.82 for lumpectomy/radiotherapy.
In a multivariate analysis, appropriate receipt of adjuvant endocrine therapy was associated with a significant improvement in overall survival (adjusted hazard ratio = 0.71, P < .001), with absolute mortality differences of 2.8% at 5 years and 6.1% at 10 years. On the basis of these data, receipt of therapy by all patients with hormone receptor–positive disease would have resulted in saving of approximately 14,630 lives over 10 years.
The investigators concluded: “From 2004 to 2013, underuse and misuse of [adjuvant endocrine therapy] have decreased for patients with breast cancer, but optimal use has not been achieved, and significant variation in care remains. The involvement of surgery and radiotherapy were among the most significant factors associated with optimal use, which underscores the benefits of team-based care to support guideline-concordant therapy.”
The study was supported by grants from the American Cancer Society, the University of Chicago, and the National Cancer Institute.
Dezheng Huo, MD, PhD, of the University of Chicago, is the corresponding author of the JAMA Oncology article.
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